Flow solder machines include heaters for heating solder to the molten state in a reservoir, pumps for forcing the molten solder to flow over a barrier to produce an artificial "wave", and transporters to transport a preheated circuit board into contact with the solder wave, thereby enabling a thin layer of solder to adhere to the board. The resulting coating of solder provides an electrical path between electrical components mounted on the printed circuit board.
Flow solder machines also include a movable conveyor arranged along each side of the machine to support the ends of the printed circuit board as the printed circuit board moves through the machine. Typically, support for the printed circuit board on a conveyor is provided by a plurality of "fingers" which grip the printed circuit board on each side and carry the printed circuit board through a fluxing station, a pre-heater station and then into contact with the molten solder.
Prior art fingers include metal pieces shaped to contact the edges of the printed circuit board to support the printed circuit board as it moves through the soldering machine. These fingers typically require cleaning and replacement due to damage caused by buildup of solder, solder flux, and dross or sludge. Where cleanup cannot be accomplished, such fingers must be discarded. Additionally, such prior art fingers may bend and distort resulting in damage to various components of the flow solder machine, such as, for example, conveyor rails, conveyors, flux air knifes, finger cleaners, and other fingers, as well as the printed circuit board itself. To repair the damaged fingers, it is necessary to shut down the flow solder machine, wait for a cool down period, remove and clean fingers, replace damaged fingers, and restart the heating cycle of the flow solder machine. This procedure is costly both from lost time and material replacement costs.
A need has thus arisen for a finger for use in supporting a printed circuit board in a flow solder machine that is easily cleanable to remove buildup of solder, solder flux and dross in an efficient maimer. A need has further arisen for a finger that will not damage flow solder machine components and printed circuit boards when stress is applied to the finger.